Automatic Test Equipment (ATE) refers to an automated, usually computer-driven, system for testing devices. A device tested by ATE is generally referred to as a device under test (DUT). ATE typically includes a computer system and one or more test instruments or a single device having corresponding functionality. ATE is capable of providing test signals to a DUT, receiving response signals from the DUT, and forwarding those response signals for processing to determine whether the DUT meets testing qualifications. For example, in some implementations, ATE may be capable of forcing voltage to a DUT and sourcing current to the DUT.
Signals are transmitted between the ATE and the DUT over one or more communication channels (or simply, “channels”). Protection circuits may be used to limit the amount of a signal, such as current or voltage, on a channel in order to protect the ATE or the DUT from damage. Protection circuits that employ resistors to sense current are known.